A String is an ordered collection of characters<\/strong> \u2014 basically, text.<\/p>\n But Swift strings are smarter and safer<\/strong> than in many other languages:<\/p>\n Quick tip<\/strong>: Use raw strings<\/strong> (#”…# ) whenever you have backslashes (\\) or quotes (“) \u2014 it saves you from writing lots of \\\\ and \\”.<\/p>\n Important things to understand:<\/strong><\/p>\n This is different<\/strong> from many older languages that count bytes or Unicode scalars.<\/p>\n Advanced interpolation (very popular 2024\u20132026 style)<\/strong><\/p>\n Modern & safe way (avoid force-unwrap)<\/strong><\/p>\n Paste your code if you want feedback!<\/p>\n What would you like to explore more deeply next?<\/p>\n Just tell me \u2014 we\u2019ll continue in the same detailed, patient, teacher-like style \ud83d\ude0a<\/p>\n","protected":false},"excerpt":{"rendered":" 1. What is a String in Swift? (the most important big picture) A String is an ordered collection of characters \u2014 basically, text. But Swift strings are smarter and safer than in many other...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[],"class_list":["post-2644","post","type-post","status-publish","format-standard","hentry","category-swift"],"_links":{"self":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2644","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/comments?post=2644"}],"version-history":[{"count":2,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2644\/revisions"}],"predecessor-version":[{"id":2646,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2644\/revisions\/2646"}],"wp:attachment":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/media?parent=2644"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/categories?post=2644"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/tags?post=2644"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
let fixedMessage = \"Namaste, Hyderabad! \ud83c\udf36\ufe0f\" \/\/ cannot be changed\r\nvar changeable = \"Hello\" \/\/ can be changed later<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n2. Creating Strings \u2013 all the common ways you\u2019ll actually use<\/h3>\n
\/\/ 1. Simple string literal (most common)\r\nlet name = \"Sneha\"\r\n\r\n\/\/ 2. Empty string (very frequent)\r\nlet empty1 = \"\"\r\nlet empty2 = String() \/\/ same thing\r\n\r\n\/\/ 3. Multi-line string (super clean \u2013 used all the time)\r\nlet aboutMe = \"\"\"\r\n Hi, I'm learning Swift.\r\n I live in Hyderabad.\r\n My favorite emoji is \ud83d\ude0a\ud83d\ude80\r\n \"\"\"\r\n\r\n\/\/ 4. String interpolation \u2013 #1 way to combine text + values\r\nlet age = 19\r\nlet city = \"Hyderabad\"\r\nlet intro = \"My name is \\(name), I am \\(age) years old, from \\(city).\"\r\n\r\n\/\/ 5. Raw string \u2013 ignores escape characters (very useful)\r\nlet regexPattern = #\"\\d{3}-\\d{3}-\\d{4}\"#\r\nlet filePath = #\"C:\\Users\\Public\\Documents\\report.pdf\"#\r\nlet jsonExample = #\"{ \"name\": \"Priya\", \"age\": 24 }\"#<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n3. Most Important String Properties & Methods (you will use these 100 times)<\/h3>\n
let message = \"Swift is modern, safe, and fun! \ud83d\ude0a\ud83d\ude80\"\r\n\r\n\/\/ Length (counts characters, not bytes)\r\nprint(message.count) \/\/ 35\r\n\r\n\/\/ Empty check (very common)\r\nprint(message.isEmpty) \/\/ false\r\nprint(\"\".isEmpty) \/\/ true\r\n\r\n\/\/ Case conversion\r\nprint(message.uppercased()) \/\/ SWIFT IS MODERN, SAFE, AND FUN! \ud83d\ude0a\ud83d\ude80\r\nprint(message.lowercased()) \/\/ swift is modern, safe, and fun! \ud83d\ude0a\ud83d\ude80\r\n\r\n\/\/ Prefix \/ suffix check\r\nprint(message.hasPrefix(\"Swift\")) \/\/ true\r\nprint(message.hasSuffix(\"\ud83d\ude80\")) \/\/ true\r\n\r\n\/\/ Contains\r\nprint(message.contains(\"modern\")) \/\/ true\r\nprint(message.contains(\"old\")) \/\/ false\r\n\r\n\/\/ Replace (returns new string \u2013 original unchanged)\r\nlet updated = message.replacingOccurrences(of: \"fun\", with: \"powerful\")\r\nprint(updated) \/\/ Swift is modern, safe, and powerful! \ud83d\ude0a\ud83d\ude80\r\n\r\n\/\/ Trim whitespace (very common for user input)\r\nlet dirtyInput = \" hello \"\r\nlet clean = dirtyInput.trimmingCharacters(in: .whitespacesAndNewlines)\r\nprint(\"[\\(clean)]\") \/\/ [hello]<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n4. Looping over characters \u2013 very common & very useful<\/h3>\n
let word = \"\u0928\u092e\u0938\u094d\u0924\u0947 \ud83d\ude0a\"\r\n\r\nfor char in word {\r\n print(char)\r\n}\r\n\r\n\/\/ Output:\r\n\/\/ \u0928\r\n\/\/ \u092e\r\n\/\/ \u0938\r\n\/\/ \u094d\r\n\/\/ \u0924\r\n\/\/ \u0947\r\n\/\/ (space)\r\n\/\/ \ud83d\ude0a<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n
5. String Interpolation \u2013 the modern, clean way to build text<\/h3>\n
let product = \"iPhone 16 Pro\"\r\nlet price = 119900\r\nlet rating = 4.85\r\n\r\nlet description = \"\"\"\r\n Product: \\(product)\r\n Price: \u20b9\\(price)\r\n Rating: \\(rating) \/ 5\r\n \"\"\"\r\n\r\nprint(description)<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nlet temp = 36.7\r\n\r\nlet health = \"\"\"\r\n Temperature: \\(temp, format: .number.precision(.fractionLength(1)))\u00b0C\r\n Status: \\(temp > 38 ? \"Fever \ud83d\ude37\" : \"Normal \ud83c\udf21\ufe0f\")\r\n \"\"\"\r\n\r\nprint(health)<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n6. Working with parts of a string (substrings, prefix, suffix)<\/h3>\n
let fullName = \"Sneha Reddy\"\r\n\r\n\/\/ First character\r\nif let first = fullName.first {\r\n print(\"First letter: \\(first)\") \/\/ S\r\n}\r\n\r\n\/\/ Last character\r\nif let last = fullName.last {\r\n print(\"Last letter: \\(last)\") \/\/ y\r\n}\r\n\r\n\/\/ First 5 characters\r\nlet firstFive = fullName.prefix(5) \/\/ \"Sneha\"\r\n\r\n\/\/ Everything after first space\r\nif let spaceIndex = fullName.firstIndex(of: \" \") {\r\n let lastName = fullName[fullName.index(after: spaceIndex)...]\r\n print(\"Last name: \\(lastName)\") \/\/ Reddy\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nlet email = \"aarav@example.com\"\r\n\r\nif let atIndex = email.firstIndex(of: \"@\") {\r\n let username = email[..<atIndex] \/\/ \"aarav\"\r\n let domain = email[email.index(after: atIndex)...] \/\/ \"example.com\"\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n7. Very Common Real-Life Examples (you will write these)<\/h3>\n
Example 1 \u2013 Clean username validation<\/h4>\n
func isValidUsername(_ input: String) -> Bool {\r\n let trimmed = input.trimmingCharacters(in: .whitespacesAndNewlines)\r\n \r\n return !trimmed.isEmpty &&\r\n trimmed.count >= 3 &&\r\n trimmed.count <= 20 &&\r\n trimmed.allSatisfy { char in\r\n char.isLetter || char.isNumber || char == \"_\" || char == \".\"\r\n }\r\n}\r\n\r\nprint(isValidUsername(\"aarav_007\")) \/\/ true\r\nprint(isValidUsername(\" a \")) \/\/ false<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nExample 2 \u2013 Simple phone number formatting<\/h4>\n
func formatIndianPhone(_ number: String) -> String {\r\n let digitsOnly = number.filter { $0.isNumber }\r\n \r\n guard digitsOnly.count == 10 else {\r\n return number\r\n }\r\n \r\n let prefix = \"+91 \"\r\n let part1 = digitsOnly.prefix(5)\r\n let part2 = digitsOnly.dropFirst(5)\r\n \r\n return prefix + part1 + \" \" + part2\r\n}\r\n\r\nprint(formatIndianPhone(\"9876543210\")) \/\/ +91 98765 43210\r\nprint(formatIndianPhone(\"987 654 3210\")) \/\/ same<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nExample 3 \u2013 Password strength indicator<\/h4>\n
func passwordStrength(_ password: String) -> String {\r\n guard !password.isEmpty else { return \"Too short\" }\r\n \r\n let lengthScore = password.count >= 12 ? 3 : password.count >= 8 ? 2 : 1\r\n \r\n let hasUpper = !password.lowercased().elementsEqual(password)\r\n let hasLower = !password.uppercased().elementsEqual(password)\r\n let hasDigit = password.rangeOfCharacter(from: .decimalDigits) != nil\r\n let hasSymbol = password.range(of: \"[!@#$%^&*()_+=]\", options: .regularExpression) != nil\r\n \r\n let variety = [hasUpper, hasLower, hasDigit, hasSymbol].filter { $0 }.count\r\n \r\n let totalScore = lengthScore + variety\r\n \r\n switch totalScore {\r\n case 6...7: return \"Very Strong \ud83d\udcaa\"\r\n case 4...5: return \"Strong \ud83d\udc4d\"\r\n case 2...3: return \"Medium \ud83d\ude10\"\r\n default: return \"Weak \ud83d\ude1f\"\r\n }\r\n}\r\n\r\nprint(passwordStrength(\"Passw0rd!\")) \/\/ Strong \ud83d\udc4d\r\nprint(passwordStrength(\"abc123\")) \/\/ Medium \ud83d\ude10<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n8. Quick Summary \u2013 Most Important String Operations<\/h3>\n
\n\n
\n \nGoal<\/th>\n Best modern code example<\/th>\n Notes \/ Tip<\/th>\n<\/tr>\n<\/thead>\n \n Build text with variables<\/td>\n “Hi \\(name), age: \\(age)”<\/td>\n Interpolation \u2013 #1 method<\/td>\n<\/tr>\n \n Multi-line text<\/td>\n “”” \u2026 “””<\/td>\n Cleanest way<\/td>\n<\/tr>\n \n Length<\/td>\n text.count<\/td>\n Counts visible characters (emoji = 1)<\/td>\n<\/tr>\n \n Empty check<\/td>\n text.isEmpty<\/td>\n Fast & clear<\/td>\n<\/tr>\n \n Upper \/ lower<\/td>\n text.uppercased(), text.lowercased()<\/td>\n Use for case-insensitive comparison<\/td>\n<\/tr>\n \n Contains substring<\/td>\n text.contains(“word”)<\/td>\n Simple & fast<\/td>\n<\/tr>\n \n Replace text<\/td>\n text.replacingOccurrences(of: “old”, with: “new”)<\/td>\n Returns new string<\/td>\n<\/tr>\n \n Trim whitespace<\/td>\n text.trimmingCharacters(in: .whitespacesAndNewlines)<\/td>\n Clean user input<\/td>\n<\/tr>\n \n Loop over each character<\/td>\n for char in text { \u2026 }<\/td>\n Each char is a Character<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 9. Small Practice \u2013 Try these now<\/h3>\n
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